Energizing controls for elevator hoist equipment of a plural car elevator system



Dec. 30. 1969 ENERGIZING CONTROLS FOR ELEVATOR HOIST EQUIPMENT Filed Jan. 20, 1967 OF A PLURAL CAR ELEVATOR SYSTEM D. L. HALL ET AL 3 Sheets-Sheet l fl-F 4 5' DEMAND MEMORY cm A ,13 DEMAND HALL CALL L v ALLOTTER MEMORY ALLs FINDER CAR B DEMAND PREFERENCE NM MEMORY FLOOR REQUIREMENT R C O ls DEMAND MEMORY A. QUEUE CAR D cAR, cm A CAR M-G SET 45 CALLS CONTROLS cm A CAR A QUEUE cAR, cAR B As CAR M-G SET CALLS CONTROLS CAR B CAR 5 QUEUE cAR, CARC CALLS V CONTROLS CAR 0 CAR 0 QUEUE by MR, CARD :5 CAR M-G SET c LLs CONTROLS CAR 0 CAR D INVENTORS M AM AT TORNEYS Dec. 30. 1969 HA| AETAI- 3,486,584

ENERGIZING CONTROLS FOR ELEVATOR HOIST EQUIPMENT OF A PLURAL CAR ELEVATOR SYSTEM Filed Jan. 20, 1967 5 Sheets-Sheet 2 CAR "A" IN GROUP SERVICE MEMORY CAR A" COINC IDE NCE DOWN I-IALL NCIDENCE DOOR IS CLOSED AILU OF SER SWIT I-I 'B"I\/IG IS OR IS QUEUE OR IS QUEUE CAR R MG OR IS QUEUE CAR CALL AT FLOOR VICE AND IVIG IS IS ON SAI CAR "D"MG IS NOT IS T INVENTORS DONIVAN L. HALL m, un. 4 m

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m5 M350 9 2. E6 0 Emma 5:3 2 u ".25. Eta o INVENTORS' DONIVAN L. HALL GERALD D. ROBASZKIEWICZ ATTORNEYS United States Patent 3,486,584 ENERGIZING CONTROLS FOR ELEVATOR HOIST EQUIPMENT OF A PLURAL CAR ELEVATOR SYSTEM Donivan L. Hall and Gerald D. Robaszkiewicz, Toledo, Ohio, assiguors to Reliance Electric Company, Euclid, Ohio, a corporation of Delaware Filed Jan. 20, 1967, Ser. No. 610,575 Int. Cl. B66b 1/24 U.S. Cl. 187-29 15 Claims ABSTRACT OF THE DISCLOSURE An elevator control for a plural car elevator system to selectively energize and deenergize hoist equipment for individual cars. Each hall call is allotted to an individual car according to the cars capability to serve the call. Deenergized hoist equipment is scaled to other factors impeding service in the call allotment consideration.

This invention relates to elevator controls and more particularly to controls for energizing and deenergizing the hoisting equipment of individual elevator cars in an interrelated manner according to the requirements of a plural car elevator system.

While the controls disclosed herein are applicable to a number of plural car elevator systems, they are particularly adapted to augment the elevator systems disclosed in the U5. patent application Ser. No. 493,973 filed Oct. 8, 1965 for Elevator Controls in the names of Donivan L. Hall and William C. Susor, and US. patent application Ser. No. 494,194 filed Oct. 8, 1965 for Elevator Controls in the names of Donivan L. Hall, William C. Susor and James H, Kuzara. In these systems the cars run only in response to calls. Calls registered in the cars, car calls, cause the respective cars to run to the landings designated by those calls. In addition, calls registered at the landings, hall calls, are assigned individually to the cars so that only one car is caused to run to each call. The assignment is based upon the capability of the car to serve the call. In the first-mentioned application the assignment is based upon the capability of the car within certain limits which are successively set such that all cars are scanned for the most favorable limits and, if none are available within those limits, the next most favorable limits are set and all cars are again scanned, the sequence continuing until a car is found with an acceptable capability to provide the hall call service.

In the second of the aforenoted applications, the assignment of the hall calls is optimized in that all cars are evaluated as to their capability to serve each hall call and an assignment is developed between the hall call and that car in the optimum condition to serve the call. In this type of system when no car calls are registered in a car and no hall call assignments are developed between hall calls and the car, the car stops and parks wherever it happens to be. Thus the elevator cars are distributed in a random fashion throughout the range of travel of cars in locations which are dependent upon the last service they provided. An augmenting feature of these systems is to provide controls which insure that at least 3,486,584 Patented Dec. 30, 1969 one car is assigned to serve a preference landing. This in general is accomplished by registering an artificial call which is assigned to a car best conditioned to respond to that call and causes that assigned car to run to the preference landing where it is maintained available for prospective passengers. The lobby landing in a building is typical of a preference landing to which this type of service is afforded.

It has been known in the prior art to deenergize the hoisting equipment of elevators when the elevators have no service requirements imposed upon them for a given interval of time. In the more common types of elevator systerns, the elevator cars are caused to run to a predetermined parking station before their hoisting equipment is deenergized. Usually such deenergization of hoisting equipment occurs when the cars are at the lobby or main preference landing. Where supervisory controls are pro vided for selecting and dispatching cars on some sort of a spacing scheme from the main or lobby landing, these selection controls have in the past been utilized as a means of determining the sequence of energization and deenergization of hoisting equipment for the individual cars. Thus it has been known to cause cars to run to a lobby and to remain at the lobby for a given interval when the system is subject to no car or hall calls after which the hoisting equipment for the individual cars is shut down. As the demands for service are imposed upon a dormant system, cars are started in a sequence determined by the selection process of the supervisory equipment such that the car selected to be dispatched away from the main landing is the first car to have its hoisting equipment energized. Usually this sequence requires that the energized car be dispatched and a new car be selected by the selecting equipment as a prerequisite to energizing the hoisting equipment of that new car,

An alternative form of control wherein a single car is permitted to park at its point of last service over the range of travel and the remaining cars of the system are retained parked at the home or main landing, also utilizes controls for deenergizing the hoisting equipment. In such a system the cars are shut down in the absence of calls allocated to those cars by their spatial relationship based upon the car position. Thus ordinarily under dormant conditions this type of system causes cars at the lobby to serve hall calls at and below the lobby landing and car calls in the lobby cars while the single dormant ear located above the lobby is initially responsive to a landing call registered anywhere above the lobby landing. Thus shutdown of the cars is based solely upon the absence for a predetermined interval of a call requiring the service of the individual car. The energization of the hoisting equipment for the individual cars is initiated on the same basis, that is, the cars located at the main landing will energize their hoisting equipment only when subjected to a landing call at or below the main landing or a car call within the car, while the single car parked in a random fashion above the main landing will energize its hoisting equipment when a call requiring its service is imposed upon the system.

The present type of system wherein a plurality of cars are randomly spaced throughout the structure served by the system and but one car services a preference landing, is not adequately served by the hoist equipment energizing control systems of the prior art. In particular, it is desirable in the aforenoted type of systems to maintain the car assigned preference landing service with its hoisting equipment energized until all other cars in the system have their hoisting equipment deenergized, since, as the system approaches and achieves dormant state, it is most probable that additional service requirements will be imposed at the preference landing. However, when additional requirements can be imposed in a random fashion, provision must also be made for complementing the call allocation to individual cars by energizing the hoisting equipment of the individual car without regard to any predetermined sequence or the original preferred sequence of shutting down those cars.

When a hall call is registered in a system having the hoisting equipment of at least some of the cars shut down, the system evaluates the capability of each car to serve the call, taking into consideration the service burden imposed upon those cars having their hoisting equipment energized, and allots the call to the car having the most favorable relationship to the call. In the case of the energized cars the system considers their separation from the call, the number of stops assigned the car between the car and the call, the number of stops assigned the car and located beyond the call, and the loading of the car. These factors are scaled to the service time they require of the car. Cars having their hoisting equipment shut down have no calls assigned and their capability to serve the call is determined by their separation from the call. In addition a bias is imposed for deenergized cars tending to concentrate call assignments in energized cars. This bias, while adjustable, has been scaled to about the energizing interval or twenty-four seconds of service time in the exemplary system where each landing of travel is scaled to one second, each intermediate stop is eleven seconds, each call beyond is six seconds, and one second for each passenger in the car. Thus if a call is five floors from a deenergized car, that cars service time would be twenty nine seconds (24 seconds of shut down bias and 5 seconds of spacing) so that any other car having a lower service time would receive the call alotment, e.g. an energized car seven floors from the call and having one stop assigned between the call floor and the car would have an eighteen second service time (7 seconds of spacing and 11 seconds of stop) and would be allotted the call in preference to the closer shut down car. If all cars are deenergized the call is allotted to the nearest car when all shut down bias levels are equal.

Registration of a call which energizes a car at the preference floor results in the energization of a second car to cause it to run to the preference floor and fill the vacancy which will be created at that floor by the departure of the car having the call allotment.

In addition, in the prior art, it has been deemed desirable to avoid the simultaneous energization of the hoisting equipment of several cars. This has been accomplished by utilizing the dispatch selection equipment as the means of sequencing the starting of the car. The present system is provided with a novel interlock feature to avoid the simultaneous energization of the hoisting equipment of a plurality of cars without being subject to the limitations of a dispatch selection sequence and a fixed order of selection of cars to be placed in an operating state.

In accordance with the above, a primary object of this invention is to improve elevator systems, particularly to improve the control of the energization and deenergization of the hoisting equipment of individual cars in a plural car elevator system.

Another object is to establish a preferred sequence of deenergization of hoist equipment of individual cars with respect to one or more cars serving preferred landings to insure that those cars have their hoisting equipment deenergized subsequent to the deenergization of cars distributed throughout the structure for general utilization.

A third object is to energize the hoisting equipment for individual elevator cars in a plural car system which has a preferred sequence of deenergization without regard to said preferred sequence.

A fourth object is to avoid the simultaneous energization of hoisting equipment for a plurality of elevator cars while avoiding any particular sequence of energization of the hoist equipment for said cars and instituting the energization in response to the development of an assignment between calls for service and individual cars.

While the present invention is applicable to the various types of hoist equipment employed in the elevator art and the auxiliary equipment controlled therewith such as car position indicator lamps and hall lanterns, it has been applied to variable voltage equipment employing motor-generator sets in the exemplary embodiment. Therefore the discussion which follows will refer to MG sets and controls therefor as interchangeable with the term hoist equipment.

The above and additional objects and features of this invention will be more fully appreciated from the following detailed description when read with reference to the accompanying drawings in which:

FIG. 1 is a block diagram of a typical system to which the controls of this invention are applicable;

FIG. 2 is a logic diagram of an individual cars hoisting equipment control circuits for controlling the energization and deenergization of that equipment;

FIG. 3 is a logic diagram of the MG set off bias as applied to the comparator and car is chosen for allotment memory for a typical car according to this invention; and

FIG. 4 is a logic diagram of the means for inserting a call for a service preference landing.

The present invention has been illustrated as applied to a four car elevator system serving thirteen landings including a lobby at the second landing. The lobby is such that entering traific is concentrated at that floor and tends to accumulate in waiting lines or queues when no car is standing at the lobby in condition to accept calls. A group supervisory control of the type disclosed in application Ser. No. 493,793 which seriallizes the allotment of hall calls to individual cars and allots the individual calls to the cars having the optimum service capability with respect thereto is the form of control to which the invention is applied.

Most of the functions performed by the supervisory control are accomplished by the equipment disclosed in the aforenoted applications. In addition the feature of providing a service augmenting control for the lobby, termed a queue control, whereby a queue call is registered to bring a car to the lobby when no car is in queue status at the lobby is disclosed in US. patent application Ser. No. 610,523 filed herewith in the name of Donivan L. Hall, Orval J. Martin and Gerald D. Robaszkiewicz for Queueing Controls for a Group of Elevators.

As shown in FIG. 1, the controls of four cars of a plural car elevator system have, as primary inputs for service requirements, one or more risers of landing buttons (not shown) which generally have been represented by the rectangle labeled hall calls and which are available to each of a plurality of the cars in the system. The cars have been designated A, B, C and D respectively, and their individual car call circuits originating at a bank of car call switches located within each car are designated by the respective labels, for example CAR CALLS, CAR A applied to individual rectangles. Registration of car calls results in the direct assignment of those calls to the car inasmuch as no other car can provide the requisite service for such calls. Hall calls are individually considered and an assignment developed between a car and the call by first scanning the landings to ascertain the location and direction of the landing of the hall call through a call finder 11. Once the call has been selected, it is applied to the allotter 12 herein its relationship to the several cars is ascertained and evaluated. In the evaluation process, factors such as the distance between each car over its then determined path of travel and the call under consideration is measured, the number of car call stops which occur before the car is found and the number of car stops which occur after the car is found are counted, the number of hall call stops assigned to the car which are encountered before the car is found and the number of hall call stops which are assigned to the car and which occur after the car is found are counted, the loading imposed upon the car is ascertained, and factors indicating special status for cars such as MG shutdown and queue car status are indicated. All of these factors are combined in a signal indicative of a total service requirement.

In one embodiment the service factor signals are developed in analog form and sealed to service time as predicted for the car. In this scaling calls encountered before the car is found and thus calls requiring stops between the current location of the car and the location of the call under consideration are given a greater weight indicative of the reduction of the cars service capability to that call than the calls which are encountered subsequent to the time the car is found. All of these factors are summed in the allotter 12 and the car having the lowest sum is assigned the call under consideration on the basis that it is the car having the optimum condition to serve that call. Thus the demand memory 13, the designation demand being applied to a hall call which has been assigned a car, for the optimum service capability car is actuated for the landing and direction in question.

In addition to these manually set inputs to the system, the system also contemplates insuring that the car be maintained available at a preference floor through a preference floor service requirement control 14, This control will be referred to as a queueing control inasmuch as it is intended to maintain service available at locations of concentrated service requirement where passengers might otherwise tend to queue up for the elevators. The queueing control is inserted through the call finder-allotter combination into the general supervisory control whereby a car is allotted to a queue call and caused to run to the preference landing. If the car is capable of accepting queueing service, its queue car assignment control, represented for example for car A by the rectangle labeled QUEUE CAR, CAR A is actuated.

The energizing and deenergizing controls for the hoisting equipment of the individual elevators are responsive to the calls for service assigned to the elevators in the form of car calls individual to each car and demands recorded in demand memories individual to each car as well as the queue car assignment circuits for each car. In the present example, the four car utilized have been provided with variable voltage hoist motor controls wherein a motor generator set is utilized to energize the hoist motor. Accordingly, in the block diagram of FIG. 1, these controls have been represented by the more common designation M-G set control for each of the cars.

In the system under consideration the M-G set control 15 is shut down when no call is assigned to the car for a predetermined period of time. This shutdown can occur when the car is located anywhere in its range of travel. The supervisory control requires the services of a car as an available car at the preference landing and to the extent that it requires the car to run to the preference landing, it is treated as a hall call for that landing. However, in the motor generator set control, this simulated hall call is not effective to maintain the motor generator set operating in the car which has accepted the preference landing service assignment. Thus the motor generator set controls permit cars to be shut down on a random basis as they lose their service requirements with the exception that the queue car is inhibited from shutting down its M-G set until all other cars in the system have had their sets shut down. This restriction imposed upon the shutdown of the sets is not imposed with the same rigorousness upon starting the sets. As a demand for service is registered in the system the allotter processes the call for allotment to a car. The start of any cars M-G set inserts a queue call if no queue car is present. Since the shutdown of the M-G set on the car previously in queue status release that status, no queue car is available to inhibit the queue call. The allotter processes the queue call allotting it to the car at or closest to the queue floor and starting that cars M-G set. Thus any elevator service in the building prepares the system to serve traffic at the queue floor.

An inhibiting cross connection between the various M-G set controls is provided to prevent a coincidence in the initiation of operation of the sets of a plurality of cars.

FIG. 2 illustrates in detail a logic circuit for a typical individual cars M-G set control. The circuit as depicted is made up of a combination of inverters, OR-gates, AND gates, timers, and flip flops, each of which can be of conventional form and advantageously have been produced utilizing solid state active elements. The circuit as depicted is modularized, conveniently on a circuit board (not shown) including the electrical interconnections and the passive circuit elements that cooperate with the active solid state elements in performing the inverting, gating and bistable switching functions. In order to further clarify the operation of the control, the designation of the significant information conveyed to the circuit by a signal, ordinarily a positive going or ground signal, is labeled on the lead adjacent the input or output pin. The primary M-G set controls for a typical car, car A, are shown in FIG. 2. The process of M-G set shutdown is accomplished in the exemplary system only after the car has stopped at a landing and the doors of the car are closed, hence the process is initiated by a signal to close the car doors in the form of a positive signal on lead 16 labeled MG STOP RE- QUEST. It is derived from OR gate 51 at its output lead 52 in response to a gating input on any one of gate 51 input leads 53, 54, 55 or 56. The signal applied on lead 53 from AND gate 57 is the conventional motor generator set shutdown signal developed following a cars completion of its service requirements and the absence of an additional requirement for a predetermined interval. This gate is inhibited for the queue car by a queue car signal applied to lead 58 and through inverter 59 to input lead 61 of AND 57. If car A is a queue car, the inverter 59 develops a negative signal on lead 61 to inhibit AND 57 and the shutdown signal passed to AND 57 over lead 62 is ineffective to pass a shutdown signal to the lead 53. If, on the other hand, the car is not the queue car and no signal appears on lead 58, and the inverter 59 passes a postive enabling signal on lead 61 to gate the AND 57 when a coincident signal is present on lead 62.

Negative logic is utilized to develop the signal on lead 62 by means of the OR gate 63, the inverter 64 and the M-G set shutdown timer 65. Thus, when OR 63 is gated, its output as applied on lead 66 resets the M-G set shutdown timer 65. When OR 63 is not gated, its lack of an output on lead 67 permits inverter 64 to issue on its output lead 68 a starting signal to the M-G set shutdown timer so that that timer at the end of a predetermined interval will issue a signal on its lead 62. A timer adjusting potentiometer 69 is coupled to the M-G set timer 65 so that the setting of the potentiometer 69 establishes the time interval to be defined by the timer. A convenient range for this time interval is from two to fifteen minutes in most elevator applications. If the car is in group service, a signal is applied over lead 71 to inverter 72 resulting in an absence of a signal in the input 73 to OR 63. This signal is utilized to reset the M-G set timer as the car is transferred from group service since the inversion in 72 results in a signal on 73 under those conditions. The timer 65 is also maintained reset if there is a car or hall call for the car. A call for a floor above the car results in a MEMORY ABOVE CAR A signal which is passed on lead 75 to OR 63. A call for the car located at a floor 7 below the car is signified by a signal MEMORY BELOW CAR A on lead 76 to OR 63. If an up hall call is registered at the landing at which the car is located, an UP HALL CALL COINCIDENCE signal is passed over lead 77 to OR 63 while a down hall call at the landing at which the car is located results in a DOWN HALL CALL COINCIDENCE signal on lead 78 to OR 63. Thus as long as a call is registered which the car is uniquely situated to serve as a car call or a hall call assigned to the car, a signal appears on one of the inputs 75, 76, 77 and 78 gating OR 63 to issue a reset signal on lead 66 to the MG set shutdown timer 65. When no such call is registered, no gating signal is supplied from those input leads and if the car is in group service, no reset signal is applied on input lead 73. Further, if the cars M-G set is running, no inhibiting signal is applied on input lead 79 and no means is available for gating the OR 63. Under these circumstances, the inverter 64 issues an M-G timer shutdown timer start signal on lead 68. This signal results in the initiation of the definition of the shutdown interval.

The M-G set running signal for the car is applied through lead 81 to inverter 82 such that while the set is running, no gating signal for OR 63 appears on the lead 79. When the M-G set is shut down, and the signal thereby removed from lead 81, inverter 82 issues a signal on lead 79 which gates OR 63 to apply a timer reset signal over lead 66 to timer 65.

The system is arranged to keep the queue car in operation until all cars not in queue status have their M-G sets shut down. It also is capable of having more than one queue floor, as a lobby and a conference floor. In this manner two or more cars can be in queue status at different floors simultaneously and all other cars must have their M-G sets shut down before the queue cars are.

The signal for the M-G set shutdown timer 65 in addition to gating AND 57 when the car is not the queue car, is also utilized to issue a shutdown signal when the car is a queue car by passing the MG SHUTDOWN TIME EXPIRED signal over lead 83 to AND 84. AND 84 is gated only when all other cars in the system have their M-G sets shut down or are queue cars. Thus if the control of FIG. 2 is assumed to be that for car A and car A is a queue car so that an inhibiting signal is imposed on AND 57 from lead 58, the timing out of the M-G set shutdown timer 65 will gate AND 84 provided car Bs M-G set is OK or it is also a queue car to apply a signal to input lead 85, car Cs M-G set is off or it is also a queue car to apply a signal to lead 86 and car Ds M-G set is off or it is a queue car to apply a signal to lead 87. Gated AND 84 passes a signal on lead 56 to the M-G set stop request OR 51.

OR 51 is also gated when car A has an out-of-service failure by a signal passed by lead 54 to gate the OR. Such out-of-service failure is derived (by means not shown) from the conventional safety circuits utilized in elevator controls including an M-G set stop switch usually located on the controller for the elevator, an A.C. overload relay for the supply to the motor of the motor generator set, a reverse phase relay and a loop overload relay in the variable voltage control of the hoist motor equipment.

Issuance of an M-G set stop request from lead 16 initiates a door closure for the car (by means not shown). When the door is fully closed, the M-G set shutdown signal is issued by the removal of the start signal on lead 89. M-G set run flip flop 88 issues a positive going signal on lead 89 to start the MG-set and maintains that positive signal to maintain M-G set operating. The flip flop has a set input 91 which conditions it to issue an M-G set start and run signal and a reset input 92 which inverts its conductive state and thereby removes the M-G set start signal to effectively issue an M-G set stop signal. The reset on lead 92 is derived from AND 93 which is gated by the M-G set stop request signal from OR 51 on input 8 94 and the DOOR IS CLOSED signal for the car passed to the gate over lead 95.

The car can also be transferred to an out of service state by the conventional external control such as an out of service switch on a control panel by the application of an OUT OF SERVICE signal to lead 96. This signal is passed on lead 96 to AND 97 and to inverter 98 which has an output 99 comprising the reset input for an out of service flip flop 101. Thus when the out of service switch is opened to remove the signal on 96, the inverter 98 issues a reset signal to the out of service flip flop over reset lead 99. In order to set the out of service flip flop, AND 97 must be gated to the set input 102. Gating of AND 97 requires coincidence of a DOOR IS OPENED signal for the car as passed on lead 103 and a CAR IS AT FLOOR TWO signal as passed over lead 104. Thus AND 97 is gated to permit the out of service flip flop operation only when the out of service switch has been operated, the car has run to the floor where the shutdown switch is located, and the door is open. Once flip flop 101 is set it institutes a transfer of the car to a state where its doors are closed through the gating of OR 51 and shuts down its M-G set by resetting flip flop 88.

In practice, no call is registered requiring the car to run to the landing where the shutdown switch is located and thus the out of service switch becomes effective only when the car incidental to its normal service reaches that landing. Once the out of service flip flop 101 is set, it issues a CAR IS OUT OF SERVICE signal on lead 55.

A car having its M-G set shutdown is placed in service by starting its M-G set through the issuance of a set signal on lead 91 to flip flop 88. The set signal is supplied from an AND gate 105 which in turn is gated with a delayed signal introduced by time delay 106 by an AND gate 107. AND 107 requires a coincidence of a service request for car A and the absence of an M-G starting operation for cars B, C and D. A service request for car A is indicated by gating OR 108 by a signal on its input lead 75 if there is a call assigned the car causing one of its memories for a floor above the car to issue a signal. Similarly, if there is a call assigned to the car through one of its memories for a floor below the car, a signal is passed on lead 76 to gate 108. If a call is registered at the floor at which the car is located, a signal is applied to lead 109 and OR 108. Thus any service request in the form of a car call (a command memory) or a hall call assigned the car (a demand memory) gates OR 108 to pass a signal over lead 111 to AND 107. If at this time car Bs M-G set is not starting, a signal is applied over lead 112 to AND 107. Similarly, if car C and car D do not have their sets starting, signals appear on leads 113 and 114 to AND 107 and the coincidence of these signals gates the AND to pass a signal on lead 115 to AND 105.

The signal applied on lead 115 is also applied to time delay 106 to lead 116 and after a suitable delay, for example ten microseconds, an enabling signal is issued on lead 117 to gate AND 105 and issue the set signal to the M-G set run flip flop. The purpose of the cascaded ANDs 107 and 105 with the intermediate time delay 106 is to provide an anti-coincidence interlock on M-G start signals. Thus if two cars were simultaneously allotted calls, an almost impossible situation inasmuch as the allotter handles calls serially in making assignments of hall calls and the cars are normally shut down with their doors closed at a time when no passengers can register car calls, there is a mutual inhibition of ANDs 105 for the several M-G set controls until the differences in the timing of the time delays 106 for the cars subordinate the gating of one AND to that of another. Intercoupling is accomplished through inverter 118 which, when no signal is imposed on the lead 116 representing a prerequisite for an M-G set run signal, issues a signal on lead 119 to gate OR 121. OR 121 issues a signal THIS CARS M-G SET IS NOT STARTING on lead 122 in response to the signal on lead 119. It also issues a signal to the effect that the cars M-G set is running as derived from lead 81.

The outputs 122 for the several M-G set control circuits are cross-connected. Thus lead 122 of car A is connected to lead 112 of the M-G set control circuits for cars B, C and D. Lead 122 for car B is connected to lead 112 of car A and lead 113 of cars C and D. Car Cs lead 112 is connected to lead 113 of cars A, B and D. Car Ds lead 112 is connected to leads 114 of cars A, B and C. Under the assumed condition of cars A and B each simultaneously having their AND gates 107 gated, both would partially enable their AND gates 105. However, the time delay 106 would prevent the gating of AND 105 and the resultant signal on lead 116 would terminate the gating of OR 121, it being assumed that the M-G set was not running for those cars and that therefore no signal was present on lead 81. With gate 121 disabled for each car, neither car would issue a signal on its lead 122. Thus the AND circuit 107 for each car would be inhibited. With each circuit inhibited, the OR circuit 121 would again be enabled. Since the speed of circuits of this nature are of the same order of magnitude but, as an inherent quality of the components utilized, they do have some differences, the faster circuit would dominate. Thus the car with the faster circuit would inhibit the car with the slower circuit and the faster cars time delay 106 would then gate AND 105 to set flip flop 88.

In practice some time is required to bring the M-G set of a car up to speed and to build up the hoist motor field. During this interval the M-G IS RUNNING signal is withheld :by the car control (not shown) and no signal is applied to lead 81. This prevents simultaneous starting of two M-G sets while the high starting currents are drawn by the sets and avoids any possibility of overloading the electrical supply to the system.

As noted in the discussion of the functions of AND 84, which issues a signal to permit an idle queue car to shut down its M-G set when all other cars are shut down or are in queue car status, a signal indicative of the state of cars B, C and D is fed respectively to leads 85, 86 and 87. This signal is derived from lead 124 of the M-G setqueue status control circuits for other cars. Thus if the .motor generator set of car A is not running, no signal appears on lead 81 and the inverter 82 issues a signal on lead 79 which gates OR 123 to issue a THIS CARS M-G SET IS OFF signal over lead 124. If the car is a queue car, a signal on lead 58 gates OR 123.

In certain applications, it is desirable to provide two preference landings, and therefore, two circuit controls so that the cars can assume a queue car status. Where multiple queue cars are utilized, since queue cars are the last to have their motor generator sets shut down, each queue car could inhibit the operation of the M-G set shutdown controls of the other queue car through the inhibition of each cars AND 84. In order to avoid this type of lockup, the interlocking signal from OR 123 is gated for a queue car so that in the shutdown control a queue car appears to other cars as a car having its M-G set off. Thus if a car is a queue car, signal is passed on lead 58 ot OR 123 and gates that OR to issue a signal on 124 enabling other queue cars in the system to shut down under the influence of their M-G set shutdown timer 65.

In order for a queueing call to be generated a car must be in group service with its M-G set on and have no M-G set stop request. A signal of this nature is made available to the systems queue circuit of FIG. 4 at lead 128 as derived from AND 125. AND 125 is gated by an M-G set is running signal as passed over lead 81 in coincidence with a CAR IN GROUP SERVICE signal as passed over lead 71, and the absence of an M-G set stop request reflected by the inverter 126 as a signal 10 on lead 127. With a signal gated through AND to lead 128, a queue call can be imposed on the system.

FIG. 4 shows the means for developing a queue call for the lobby floor. Such a call is imposed when no car is in queue status at the lobby, no circumstances exist which with its M-G set operating. The above conditions gate AND 129 to issue an INSERT LOBBY UP CALL on lead 131. If any car is in queue status at the lobby, a condition it achieves (by means not shown) when no other car is in queue status at the lobby, when the car to be assigned queue status is at the lobby, has no calls assigned, is in group service, is set for an up destination direction and has no door close request, it issues a signal on the appropriate input lead to OR 132 as CAR A IS QUEUE CAR. When OR 132 is gate-d it causes inverter 133 to issue an inhibit signal on lead 134 to AND 129. Thus an enable signal is present on lead 134 only when no car is in queue status.

Lead 135 to AND 129 applies a signal which inhibits the insertion of a lobby up call by AND 129. Such an inhibit is desired when the isolation of one car from general service imposes an unwarranted burden on the system. One such condition occurs when the system has one or more down hall calls registered greater than a predetermined interval which generally is chosen as a reasonable period to answer and cancel such calls, A lOIlg call registration interval imposes a positive signal on lead 136. This signal is inverted to an inhibiting signal to AND 129 by inverter 137. Thus the absence of a long hall call registration interval permits inverter 137 to enable AND 129.

Any car having its M-G set on and in group service will apply a gating signal to OR 138 as for car A on lead 128 from FIG. 2. When gated, OR 138 enables AND 129 to insert a lobby up call.

Where two or more queue floors are employed the circuit of FIG. 4 is duplicated to provide a means for inserting queue calls for each queue floor. In such instances the identification of queue cars is individual to the queue floor. Thus the feed to OR 132 for the lobby queue floor typically would be CAR IS A LOBBY QUEUE CAR and if the sixth floor were a second queue floor the OR corresponding to 132 for the sixth floor queue circuit would be fed by a signal CAR IS A SIXTH QUEUE CAR for each car. Further, if the queue service were to be downward from the sixth floor the conditions for admitting a car to sixth floor queue service would require that the car be set for a down destination direc tion instead of up as for the lobby.

Another modification with plural queue floors is to substitute an AND for OR 138 for the queue call insertion circuit for all but the primary queue floor. For example, when the lobby is the primary queue floor, a lobby up call is inserted as shown in FIG. 4 when any one car has its M-G set on and is in group service (a positive signal is present on lead 128), provided all other lobby queue call conditions are met. A sixth queue fioor call, a sixth down call, is inserted with an AND substituted for OR 138 only when all cars have their M-G sets on and are in group service to apply positive signals on each cars lead 128 and all other sixth queue call conditions are satisfied.

The means for allotting a call to a car is represented in FIG. 3 to illustrate the effect of shutting down the M-G set for the car. As outlined above, allotment between a call and a car is employed by the exemplary system to cause operation of but one car in response to a hall call. The allotment is determined by generating a signal for each car having a voltage level scaled to the predicted time required of that car to serve the allotment call and simultaneously comparing those individual car signals with a ramp signal which increases its voltage level with time beginning at the completion of the development of the predicted service time signals for the cars. The comparison of the ramp signal as it appears on lead 139 is made for each car in its comparator 141 which also receives a SERVICE TIME VOLTAGE signal on lead 142. Coincidence of the voltage levels on leads 139 and 142 causes comparator 141 to issue a set signal on lead 143 to the set input s of car chosen memory fiip flop 144. The flip flop 144 issues on lead 145 a THIS CAR CHOSEN FOR ALLOTMENT signal to a gating input of each of the cars demand memories (not shown). That demand memory for the allotment call is enabled for each other. Thus the allotment call demand memory for the chosen car is set to gate OR 108 of FIG. 2 and set M-G set run flip flop 88 to issue a M-G SET signal for that car.

The car chosen memory in the set condition is reset by a positive signal on lead 146, applied to each cars flip flop 144, when the next allotment is to be performed.

SERICE TIME VOLTAGE on lead 142 is derived from operational amplifier 147 individual to the car in response to the input signal on lead 148. That signal is made up of summed analog signals for the car representing its distance from the allotment call, the number of commands and demands for the car for floors between the car and the allotment call, the number of commands and demands for the car for floors separated from the allotment call by the car, car loading, and car queue status as applied on lead 149. A bias signal representative of an additional predicted service delay in starting the M-G set for the car is added at lead 151 to the ANALOG AMPLIFIER INPUT GRID signal on lead 149 when the M-G set of the car is shutdown. This signal is generated by buffer amplifier 152 in response to a signal from inverter 153. Inverter 153 is activated by the absence of a signal on lead 81 as derived from the M-G set run switch (not shown) in the circuits supplying power to the set. The signal added at lead 151 is adjusted in weighting adjustment 154 as derived from the setting of potentiometer 155. A signal scaled to about the starting time required to bring an M-G set up to speed and set the hoist equipment to drive the car is imposed, equal to 24 seconds of predicted service time in the exemplary structure serving thirteen floors.

With the M-G shutdown bias effective on those cars having their M-G sets shut down, a registered hall call tends to be allotted to a car having its M-G set running provided it is not so burdened and disposed with respects to the floor of the allotment call as to have a greater predicted service time than that of the sum of the M-G shutdown bias and the car to allotment call spacing of any shut down car. As between shutdown cars, the closest car tends to receive the call allotment since the sum of its M-G shutdown bias and its allotment call to car spacing signal is the first to be coincident with the ramp signal.

When all cars have their M-G sets shutdown, a registered hall call is allotted to the car closest to the floor of the call provided equal M-G shutdown bias levels are imposed on each car. Once the M-G set is started for the car receiving this allotment a signal on lead 128 gates OR 138 of FIG. 4. At this time no INHIBIT QUEUE CIRCUIT signal is present on lead 136. Hence AND 129 is enabled to be responsive to the absence of a queue car as indicated by a positive signal on lead 134 and will insert a lobby up call. Since the shutdown of the M-G set for the queue car results in its loss of queue status, each initial operation of the M-G set where all cars have had their sets shut down will result in the insertion of a lobby up call except if the initiating call coincides with the queue call floor and direction. If the car whose set has been started is best situated to receive the allotment of the queue call such allotment will have no further effect upon the shutdown cars. The started car will run to its call and then the queue floor where it will enter queue status, cancel the queue call, and if not assigned a call within the interval of timer 65, will shut its doors and shut down its M-G set. If the started car were to be burdened to a level producing a total signal on its lead 142 to its comparator 141 in excess of the signal on another car representing its service time to the queue call as made up of M-G start time and travel time, that second car would receive the queue calls as an allotted call and therefore would have its M-G set started.

The manual registration of a lobby up hall call results in the starting of the M-G set of a car at the lobby most frequently the car which shut down at a time it was the lobby queue car. The starting of the M-G set for that car causes its doors to open and cancel the manually registered demand of the allotted lobby up call. If the person who registered the hall call enters the car and registers a car call for a destination, the queue status of the car is released (by means not shown) and the lobby up queue call reinserted. As shown in detail in the copending United States patent application entilted Queueing Controls for a Group of Elevators Ser. No. 610,523 filed in the names of Donivan L. Hall, Orval J. Martin and Gerald D. Robaszkiewicz, a queue memory retains the informtaion that a car has been in queue status so long as it remains at a queue floor in order to avoid reallotment of the queue call to that car. Thus another car has the queue call allotted and its M-G set started so that its runs to the queue floor and assumes the queue status.

As a second example, consider a hall call for a floor in the upper part of the building allotted to a car in the upper part of the building. Such a car starts its M-G set and while it runs to the floor the inserted up lobby queue call is allotted. This allotment is to the car having the lowest service time voltage signal. It the running car has a travel distance to the queue call signal which when added to its stop signal for the call which initiated its service is less than the M-G bias signal for the car having its set shut down at the queue floor, that car will be allotted the queue call. If on the other hand its signal is greater than the M-G bias for the car at the queue floor, the car at the queue floor will be allotted the queue call and start its M-G set.

From the above description it will be seen that the present invention affords an inter-related control of the starting and stopping of motor generator sets without the detrimental effects of a rigorous sequencing of the starting and stopping of cars in certain conditions or perdetermined cars. Thus any car can be a queue car or a randomly parked car and be subject to the M-G set start and stop controls.

Further, the random nature of the sequence of call assignments to cars can be taken advantage of in starting the cars to serve those calls. Despite the flexibility, the system is arranged to continue the operation of the motor generator set for queue cars until all randomly parked cars have had their sets shut down and it further inhibits the simultaneous starting of cars. In addition, it accommodates itself to two or more queue cars where those cars are the last to shut down and yet can be shut down after the randomly parked cars have had their sets shut down.

The present system has been described with respect to a type of elevator hoisting equipment utilizing a motor generator set. However, it is to be appreciated that it is applicable to other types of hoisting equipment, for example. A.C. hoist motors and rectifier-supplied D.C. hoist motors. Accordingly, the system can be considered as a control for the energization and deenergization of hoisting equipment for an elevator system.

Having described the invention, we claim:

1. An elevator system comprising a plurality of cars serving a plurality of floors, hoist equipment for each car, means for each car for controlling the energization of said hoist equipment, means for each car for registering car calls for service by said car, means for registering hall calls for service by said cars, an alloter responsive to register of a hall call to develop an individual service assignment between each registered hall call and an individual car, means for ascertaining the travel distance for each of said cars to the floor of a registered hall call which is being assigned by said allotter, means for actuating said controlling means for each car to deenergize said hoist equipment of said car at the floor at which it concludes service to call for said car, means establishing a service capability criterion for each car as a function of each car call for said car, means establishing a service capability criterion for each car for each hall call assigned to said car, means establishing a service capability criterion for each floor of travel distance for each car to the floor of a registered hall call being assigned, means in said allotter for summing said service criteria for each of said cars, means in said allotter for actuating said assigning means for a call being assigned for the car having the optimum summed service criteria, and means responsive to the assignment of a hall call by said allotter to a car having said equipment deenergized to actuate said controlling means for said hoist equipment to an energized state.

2. A combination according to claim 1 wherein said allotter service capability criteria of each car includes the state of energization of said hoist equipment for said car whereby said allotter has a preference of allotment to a car having its hoist equipment energized.

3. A combination according to claim 2 wherein said service capability criteria is scaled to predicted service time to said call by said car and said predicted service time for each car having its hoist equipment deenergized includes an element scaled to the time interval required to complete energization of said hoist equipment.

4. A combination according to claim 1 including means to sense the presence of a car at a given floor, and means to inhibit the transfer of said controlling means of said car at said given floor to a state deenergizing the hoisting equipment of said car until every other car in said system has its hoisting equipment deenergized.

'5. A combination according to claim 1 including means to assign a car to serve a preference floor, and means to inhibit the transfer of said controlling means of said car at said given floor to a state deenergizing the hoisting equipment of said car until every other car in said system has its hoisting equipment deenergized.

6. A combination according to claim 1 including means to sense the presence of a car at a first preference floor, means to sense the presence of a car at a second preference floor, and means to inhibit the transfer of said controlling means to said car at said first preference floor to a state deenergizing the hoisting equipment of said car until every other car in said system has its hoisting equipment deenergized or is located at said second preference floor.

7. A combination according to claim 1 including means to assign a car to serve a first preference floor, means to assign a car to serve a second preference floor, and means to inhibit the transfer of said controlling means of said car assigned to serve said first preference floor to a state deenergizing the hoisting equipment of said car until every other car in said system has its hoisting equip ment deenergized or is assigned to serve said second preference floor.

8. A combination according to claim 1 including means to insert a hall call for a preference floor in response to a coincidence of the absence of a car assigned to serve said preference floor and the presence of at least one car having its hoisting equipment energized, said allotter functioning to a car to preference service at said preference floor, means to release said assigned car from preference service in response to the deenergization of said cars hoist equipment, means to inhibit the allotment of said inserted call to a car which has been released from preference service at said preference floor and which has not departed from said preference floor since said release, whereby two cars have their hoist equipment energized in response to allotment of a call to a car at said preference floor when all cars have their hoist equipment deenergized.

9. A motor generator set control for an elevator system including a plurality of cars serving a plurality of landings, car and hall call registering means, and means for assigning each call to that individual having the optimum service capability with respect to said call, comprising, an OR gate for each car responsive to a call assigned to the car for that set or to a hall call for the landing at which the car for that set is stopped, a timer for each car for defining a predetermined time interval actuated by the absence of a signal from said OR gate and reset by the presence of a signal from said OR gate, means to shut down each motor-generator set in response to expiration of the predetermined time interval, and means for each car to start the motor-generator set of said car in response to the assignment of a call to said car.

10. A motor generator set control for an elevator system including a plurality of cars serving a plurality of landings, car and hall call registering means, and means for assigning each call to that individual car having the optimum service capability with respect to said call, comprising, means to shut down each motor-generator set when the car for that set is assigned no calls and is located at the landing of its last assigned call, means for each car to start the motor-generator set of said car in response to the assignment of a call to said car, means for assigning a car to a preferred service at a preference landing and means for each car responsive to the absence of assignment for said car to enable said means to shut down said cars motor generator set and in the presence of an assignment for said car to inhibit said shut down means.

11. A combination according to claim 10 including means to inhibit the operation of said shutdown means for the car assigned to serve the preference landing while the motor-generator set of any other car in said system is operating, said means to start the motor-generator set of each car being independent of said means for assigning said car to serve a preference landing.

12. A combination according to claim 10 including means to shutdown the motor-generator set of the car assigned to said preference landing in response to the coincidence of the absence of a call assigned to said car and the absence of operation of the sets of all other cars in said system.

13. A motor generator set control for an elevator system including a plurality of cars serving a plurality of landings, car and hall call registering means, and means for assigning each call to that individual car having the optimum service capability with respect to said call, comprising, means to shut down each motor-generator set when the car for that set is assigned no calls and is located at the landing of its last assigned call, means for each car to start the motor-generator set of said car in response to the assignment of a call to said car, means to assign each car to an out of service status, means responsive to the presence of each car at a predetermined landing, a door for each car, means responsive to the open state of said door for each car, and means for each car to shutdown the motor generator set of said car in response to a coincidence of an out of service assignment for said car, the presence of said car at said predetermined landing, and the open state of the door for said car.

14. A motor generator set control for an elevator system including a plurality of cars serving a plurality of landings, car and hall call registering means, and means for assigning each call to that individual car having the optimum service capability with respect to said call, comprising, means to shut down each motor-generator set when the car for that set is assigned no calls and is located at the landing of its last assigned call, means for each car to start the motor-generator set of said car in response to the assignment of a call to said car, means 1 5 for each car to generate a signal during the interval said set of said car is not starting and an AND circuit for each car for issuing a set start signal for said car and responsive to a coincidence of signals from said last mentioned means of every other car of said system and a signal for said means assigning a call to said car.

15. A combination according to claim 14 including a second AND circuit for each car having an input coupled to the output of said first mentioned AND circuit for said car, a time delay circuit for each car having an input connected to the output of said first mentioned AND circuit for said car and an output connected to an input of said second AND circuit for said car, an inverter circuit for each car having an input connected to the output of said first mentioned AND circuit for said car and an output connected to said means for said car to generate a signal during the interval said set of said car is not starting whereby said first mentioned ANDs of said cars are interlocked to prevent sustained simultaneous operation of a plurality of said first mentioned ANDs.

References Cited UNITED STATES PATENTS 3,376,952 4/1968 Inuzuka et a1. 187-29 3,379,284 4/1968 Yeasting 18729 ORIS L. RADER, Primary Examiner W. E. DUNCANSON, JR., Assistant Examiner f) H! U CERT? FICA'IF, U 1* (10K lilfiilllON Patent No. 3,486,594 Dated December 30, 1969 Inventofls) I DONIVAN L. HALL and GERALD D ROBASZKIEVICZ It is certified that error appuzrrs in tire above-:Ldmmiiien patent and that said LettersPatent are hereby corrected as shown below:

Column 4, line 42, "493,793" should be 493,973

Column 5, line 17, "sealed" should be scaled Column 10, line 5, after "which insert dictate against queue service,

and a car is in group service Column 11, line 17, "SERICE" should be GERVICE Column 13, line 5, "call" should be calls line 47, "to", first ocourence, should be of 7 1 55, after first occurrence, insert assign Column 14, line 6, after "individual" insert car Signed and sealed this 1st day of October 1974,

(SEAL) fattest:

MCCOY M. GIBSON JR. 2. MARSHALL AJANN Attesting Officer Commissioner of Patents 

